Suspension Bridges

Activity Overview

Students really enjoy this Activity – presumably because of its construction challenges, the elegant form of the resulting structure and the understanding it provides of how suspension bridges work.

In this Activity, students consider the difficulties of building a long-span bridge that cannot be accessed or supported from below. They consider how the various components must be assembled in proper sequence. They also come to understand how the towers, cables, suspenders and decking work together as a structural system. Finally, they learn about the inherent flexibility of cable-supported structures and about ways to reduce this flexibility.

Learning Objectives

By the end of the activity, students should be able to:

  1. Explain the challenges of constructing a long-span bridge which cannot be accessed from below
  2. Illustrate how the bridge components must be assembled in the correct order
  3. Explain how the towers, cables, suspenders and decking function as a system to carry traffic loads
  4. Demonstrate the flexibility of a cable-supported structure
  5. Illustrate how this flexibility can be reduced by deck stiffening

Tips for Using the Activity

Students should be encouraged to enjoy the Activity.

They should not be rushed or under pressure to obtain the “correct answer” or a high grade.

Instead, they should be encouraged to think about the challenges of long-span bridge construction, and hostile construction environments.

They should be given credit for thinking about and explaining how the components of the system (towers, cables and decking) work together as a structural system.

Equipment Design

This was one of the more expensive models to build, but it is also one of the most instructive. For the bridge to work well, the components need to be fabricated with precision, and the chain must be of the right type, with the suspenders positioned carefully and cut to the right length.

Additional Information

See the Downloadables section for more information on this activity.